Genesis, mechanism, and stability of the Dongmiaojia landslide, yellow river, China

• The Dongmiaojiao landslide is an example of a typical bedding plane landslide.
• The geological structure and failure mechanism of the Dongmiaojia landslide are presented.
• A DDA strength reduction method is applied to study the stability and failure process of the landslide.
• The analysis results show the stability coefficient of the landslide to be 1.07.

Bedding plane landslides are common in nature, and usually occur in formations with an alternating sequence of soft and hard rock beds. The Dongmiaojia landslide, located near the Xiaolangdi hydraulic project on the Yellow River, is a typical bedding plane landslide formed in an alternating sequence of soft and hard rock beds. Using field data of this landslide, we systematically analyzed the genesis, mechanism, and stability of this type of bedding plane landslide. According to the geological structure and the deformation characteristics, we divided the landslide into three parts: the front colluvial mass, the middle and rear sliding-deformation mass, and the rear tension-deformation mass. The failure mode of the Dongmiaojia landslide is mainly retrogressive creep deformation under the action of the combined endogenic and exogenic geological processes. An improved DDA strength reduction method was applied to study the stability and the failure process of the Dongmiaojia landslide. The analysis results produced a stability coefficient of the landslide equal to 1.07; the numerical simulation analysis showed that the failure mode of the landslide is a compound failure process which consists of forward sliding of the middle part and retrogressive sliding of the rear part, with the front colluvial mass acting as a support effect for the down-sliding of the whole landslide mass.